1. Field
The present application discloses a test handler for transferring a test tray containing packaged semiconductor chips so that electrical tests can be performed on the packaged chips, and a process for testing the semiconductor chips using the handler.
2. Background
A test handler may be used to perform electrical tests on packaged chips at the conclusion of a packaging process. Such a handler transfers packaged chips from a user tray to a test tray and supplies the test tray containing the packaged chips to a tester. The tester includes a test board having a plurality of sockets. The packaged chips in the test tray are brought into contact with the sockets to perform an electrical test on the packaged chips. The packaged chips are graded according to the test results, and the handler transfers the graded chips from the test tray to appropriate user trays based on the grading.
FIG. 1 is a top view of a configuration for a conventional hander. FIG. 2 is a view of a path which a test tray T follows in the handler. The reference numbers in FIG. 2 indicate the locations within the handler where the test tray T is positioned.
As shown in FIGS. 1 and 2, the handler 10 includes a chamber system 11, a loading stacker 12, an unloading stacker 13, a picker system 14, a buffer unit 15, and an exchanging site 16. The chamber system 11 includes the first chamber 111, a second chamber 112, and a third chamber 113. Within the first chamber 111, the packaged chips in the test tray T are heated or cooled to a testing temperature which is predetermined depending upon a user's quality requirements. After the packaged chips are heated or cooled to the testing temperature, the test tray is transferred from the first chamber 111 into the second chamber 112.
Within the second chamber 112, the packaged chips in the test tray T are brought into contact with sockets of a test board A. Thereafter, electrical tests are performed on the packaged chips. This is referred to as “a testing process”. The test board A is coupled to the second chamber 112.
After the packaged chips are tested, the test tray is transferred from the second chamber 112 into the third chamber 113. Within the third chamber 113, the packaged chips in the test tray T are cooled or heated to room temperature.
Thereafter, the test tray T is transferred from the second chamber 113 to the exchanging site 16.
A plurality of user trays, each containing packaged chips intended for the electrical tests, stay at the loading stacker 12. A plurality of user trays, each containing tested packaged chips, may stay at the unloading stacker 13.
The picker system 14 includes a first picker 141, a second picker 142, a third picker 143, and a fourth picker 144. Each of the first picker 141, the second picker 142, the third picker 143, and the fourth picker 144 pick up a plurality of the packaged chips and transfer the chips between the user trays, a buffer and the test tray. The first picker 141 and the second picker 142 transfer the packaged chips intended for the electrical tests, from the user trays at the loading stacker 12 to a test tray T located at the exchanging site 16. This is referred to as a “loading process”. More specifically, the first picker 141 picks up the packaged chips intended for the electrical tests from the user trays at the loading stacker 12 and places them on the buffer unit 15. The first picker 141 moves in X-axis and Y-axis directions. The first picker 141 also ascends and descends.
The second picker 142 picks up the packaged chips intended for the electrical tests from the buffer unit 15 and places them into a test tray T at the exchanging site 16. The second picker 142 moves in the X-axis direction, and also ascends and descends.
The third picker 143 and the fourth picker 144 transfer the tested packaged chips from a test tray T at the exchanging site 16 to the user trays at the unloading stacker 13. This is referred to as an “unloading process”. More specifically, the third picker 143 picks up the tested packaged chips from a test tray T at the exchanging site 16 and places them on the buffer unit 15. The third picker 143 moves in the X-axis direction, and also ascends and descends. The fourth picker 144 picks up the tested packaged chips from the buffer unit 15 and places them into the user trays at the unloading stacker 13. The fourth picker 144 moves in the X-axis and Y-axis directions. The fourth picker 144 also ascends and descends.
The picker system 14 may include a plurality of the first pickers 141, a plurality of the second pickers 142, a plurality of the third pickers 143, and a plurality of the fourth pickers 144.
The buffer unit 15, where the packaged chips are temporarily placed, moves in the Y-axis direction. The buffer unit 15 may include a first buffer 151 and a second buffer 152. Further, each of the first and second buffers may include individual elements that can move independently in the Y-axis direction.
The first buffer 151 is provided adjacent to one side of the exchanging site 16. The packaged chips intended for the electrical tests are placed on the first buffer 151.
The second buffer 152 is provided adjacent to the other side of the exchanging site 16. The tested packaged chips may be placed on the second buffer 152.
When a test tray T containing chips that have already been tested arrives at the exchanging site 16, the tested packaged chips are picked up from the test tray T, and the packaged chips intended for the electrical tests are placed into the empty test tray T. The third picker 143 picks up the tested packaged chips from the test tray T and places them on the second buffer 152, and then the second picker 142 picks up the packaged chips intended for the electrical tests from the first buffer 151 and places them into the test tray T.
After the tested packaged chips are replaced with new packaged chips intended for the electrical test at the exchanging site 16, the test tray T is transferred from the exchanging site 16 to the chamber system 11. After the packaged chips are tested by the tester within the chamber system 11, the test tray T is transferred from chamber system 11 to the exchanging site 16.
The exchanging site 16 may further include a rotating unit 161. The rotating unit 161 rotates a test tray containing the packaged chips intended for the electrical tests from a horizontal position to a vertical or upright position. The test tray T remains in the upright position during its transfer within the chamber system 11.
The rotating unit 161 may rotate an upright-positioned test tray containing tested packaged chips from a vertical position to a horizontal position. The test tray T remains in the horizontal position while the tested packaged chips are picked up from it and then the new packaged chips intended for the electrical tests are placed into it.
The conventional handler 10 has several disadvantages. For the sake of efficiency, the tested packaged chips are picked up from the test tray T at the same time that the packaged chips intended for the electrical tests are placed into the empty test tray T. Because the loading and unloading operations are conducted at the same time, the various pickers may interfere with each other during the loading and unloading process. This not only makes it difficult to effectively control the unloading and loading processes, but also puts a limit on reducing the time for unloading the tested packaged chips from the test tray T and loading the packaged chips intended for the electrical tests into the test tray T.